Annual report pursuant to Section 13 and 15(d)

STOCK-BASED COMPENSATION - Narrative (Details)

v3.20.4
STOCK-BASED COMPENSATION - Narrative (Details)
 1 Months Ended 12 Months Ended
Jul. 01, 2020
USD ($)
May 31, 2013
shares
Dec. 31, 2020
USD ($)
plan
shares
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of share-based award plans | plan     1    
Increase in reserve under share-based award plan, number of shares (in shares) | shares   11,000,000      
Total income tax benefit recognized for stock-based compensation expense     $ 13,000,000.0 $ 12,200,000 $ 9,700,000
Stock options vesting percentage for each year of completed service     33.00%    
Stock options expiration periods     10 years    
Total shareholder return, period     3 years    
Cumulative adjusted earnings per share, period     3 years    
Minimum percentage of target to which shares may be issued     0.00%    
Maximum percentage of target to which shares may be issued     200.00%    
Percentage of target that shares may be issued     100.00%    
Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based payment award options nonvested number of shares | shares     290,033    
Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based payment award options nonvested number of shares | shares     580,066    
Stock Options          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Total intrinsic value of stock options exercised     $ 20,300,000 18,600,000 13,300,000
Total unrecognized compensation cost     $ 7,100,000    
Total unrecognized compensation cost, weighted-average period of recognition     1 year 3 months 18 days    
Stock Options | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock awards vesting periods (up to)     3 years    
Nonvested Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Total unrecognized compensation cost     $ 39,900,000    
Total unrecognized compensation cost, weighted-average period of recognition     1 year 7 months 6 days    
Total weighted-average fair value of nonvested stock vested, based on the vesting date     $ 44,000,000.0 32,600,000 50,200,000
Total weighted-average fair value of nonvested stock vested, based on the grant date     $ 32,500,000 $ 30,500,000 $ 40,400,000
Nonvested Stock | Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock awards vesting periods (up to)     1 year    
Nonvested Stock | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock awards vesting periods (up to)     3 years    
Employee Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
ESPP annual amount of employee withholdings $ 25,000        
ESPP, discount on closing stock price (as a percent) 5.00%        
Employee Stock | Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
ESPP, option to withhold amount of salary (as a percent) 1.00%        
Employee Stock | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
ESPP, option to withhold amount of salary (as a percent) 10.00%